A Reaction of One Sort or Another
by Consulting-Wreck
Summary: "Bloody hell, Sher-" Sherlock was slightly rocking back and forth, drumming his fingers rapidly on his leg. John had to do a double take, "Sherlock," he started quietly, "are you-" "Don't." he hissed. "-scared?"
1. Effect and Cause

It sounded ridiculous, a person /slowing down/ after eating just a tiny bit, but the more John got used to Sherlock's body language he noticed that, indeed, Sherlock seemed to slow exponentially after eating. Within several minutes of ingesting anything Sherlock usually walked slower, the way he walked on the outer edges of his feet indicating that he was trying to keep from jostling his stomach. It was only after John made made Sherlock eat lunch, and he spent the rest of the night curled up in his chair in obvious (to John at least) discomfort, that he brought it up.

"Sherlock, have you ever been tested for allergies?"

Sherlock looked up indignantly, "Surely you can tell that I am not having an allergic reaction, _Doctor Watson_."

"Not all allergic reactions are anaphylactic shock or hives."

"I am not allergic to anything." Sherlock waved his hand, as if he was shooing away the very thought.

"You try to avoid eating because you feel ill after." John stated.

"No," he insisted, "it's because eating sows me down."

John rolled his eyes, "It slows you down because you feel ill."

Sherlock says nothing in response and looks away.

"Just answer some questions for me, okay? How does your stomach feel after eating?" John waits to see if he's blessed with an answer.

Sherlock wrinkles his nose, "Nauseous, a bit bloated even after small amounts."

John nods, "Any vomiting?"

There is a long stretch of silence "Occasionally," Sherlock admits, "Usually self induced to get rid of the ill feelings."

"Alright," John keeps his voice neutral, but he is upset to hear that his friend, who already eats so little, would do that to himself, "Any diarrhea?"

"Yes," is the immediate response.

"Right then," John reached for his laptop, "I'm making an appointment as soon as possible to get you tested."

* * *

Three days passed before the day of Sherlock's appointment arrived. John had to bribe Sherlock with experiment privileges to get him out the door. They were just about to walk in to the office when Sherlock abruptly stopped walking.

"Seventy-two." he said.

John gaped, "No. No, you agreed to forty-eight!"

"I've decided a visit to an allergist is definitely worth more than two days of fridge time." Sherlock looked over at a passing car.

"I'll give you fifty-five hours." John shuffled on his feet. He had to convince Sherlock to go in, no mater how long there would be a head in their fridge.

Sherlock continued to look at anything but John.

"Fine. You can have your three days. Let's go." He took a had a hand on the door handle when he noticed Sherlock still hadn't moved. "Bloody hell, Sher-"

Sherlock was slightly rocking back and forth, drumming his fingers rapidly on his leg.

John had to do a double take, "Sherlock," he started quietly, "are you-"

"Don't." he hissed.

"-scared?"

Sherlock had a strange expression on his face that looked a mix of disgust and holding back tears. He opened his mouth to say something, but closed it and fixed his gaze on the golden numbers above the door.

Looking at his watch John made a small, sympathetic noise, "Do you want to take a walk? We've can have five minutes, but then we really need to get in there."

Sherlock, obviously against John's pity, stormed inside and sat in one of the overly cushioned waiting room chairs.

Sighing. John walked up to the desk to sign in, "Appointment for Sherlock Holmes." he said to the woman at the computer.

The older woman clicked the mouse a few times, "This is your first time here?"

John pointed back at Sherlock, "His, yeah. Not too pleased about it either."

She smiled, "Well then, he just needs to fill this sheet out with his details and return it when finished." She passes John a clipboard, "Both sides."

"Thanks." John walks over to where Sherlock is sulking. "Here, fill this out."

Sherlock yanks the form out of John's hands and fills it out at lightning speed, then he takes it to the front desk himself.

"Alrighty," the woman says, "the doctor can take you back right now, his last appointment was a no show."

Sherlock freezes, for a short moment John thinks he might faint, then he turns to John, "Coming?"

John stands, but the desk woman laughs, "Oh, no, dear. We don't allow non-family in the rooms."

When Sherlock's right knee buckles and he nearly falls before straitening it again the desk woman doesn't notice, but John does and his stomach clenches. Something is _wrong_.

Three chapters of his book later a different woman with red hair hands him some more papers. "What happened?" he asks quickly.

"What? Nothing, your friend just said he needed the loo and to give you the bill and the results." the lady hands him a pen and he signs the bill quickly and writes a check.

"Where are the bathrooms at?" Sherlock hardly ever uses public toilets, and when he does it isn't in a place he hates.

The woman points him in the right direction and he goes quickly, hoping to catch Sherlock before he makes a grand disappearance. John arrives just in time to nearly be hit in the face by the opening door. "Hey!" Looking up he realizes it's Sherlock, "Watch where you're- shit, are you alright?"

Sherlock's eyes are red and his lower lip is trembling slightly. "John," his voice cracks and he clears his throat, "John, I would like to go home now."

"Sure, yeah." John is about to start walking when he pauses, "Would you, uh, would you like a hug first?"

Sherlock glances around and peeks down the hall before nodding unsurely.

It's an awkward hug, Sherlock is stiff as a board and John isn't sure what would be helpful versus what would put Sherlock off. John pats Sherlock on the back before pulling away. "Good?"

Now Sherlock's eyes are shining and he simply nods once before walking away with longer-than-usual strides, only stopping to let John catch up after he was out of the building.

When John is back at Sherlock's side he sees him tilting his phone around. Looking at his eyes, John realizes.

Sherlock leans closer to the phone screen and swears under his breath. He turns to John, "Have you got the results?"

He flaps the small stack of papers, "Yeah. Want to look?"

"In the cab." Sherlock states, waving one down at that exact moment, as if some sort of author in the sky writing their lives liked to make things more dramatic. Sherlock climbs in and John follows.

John centers the papers on his lap, "Right then, the test results." He doesn't miss the sudden concerned glance in the rear-view mirror from the cabbie, so he adds, "Time to see if you're allergic to anything, Sherlock."

Sherlock is attentively paying attention to John, for once.

"The moment of truth." John says and opens the folder. The top sheet was a list of what had been tested and the highlighted items were what tested positive. "Oh, God."

"What? What is it? Peanuts? Shellfish?" Sherlock looked concerned.

John looked over the sheet again, there were fourteen items highlighted, nine of which were food items. "Birch, dandelion, poison ivy, ryegrass, and meadow grass," he read off.

Sherlock sighed and grinned, "I thought it would be something serious. Allergies to pollen can be avoided by simple shots. You could even bring them home from work."

Clearing his throat, John continued, "Onions," Sherlock's cheeky grin falters, "tomatoes," the grin is gone now, replaced by a look of confusion, "green peas, filbert-" he breaks off and looks to Sherlock in confusion, "Filbert?"

Sherlock blinks to snap himself out of his daze, "An alternate title for hazlenuts." he explains.

Nodding, John takes a breath and continues, "Cinnamon, flounder, milk, eggs, and wheat. That's everything."

Sherlock takes a deep breath, opens his mouth to say something, then just shakes his head.

"We need to cut all of that out for a month at least to see how you feel," John quietly explains what Sherlock probably already knows, "Then we can try adding one thing back for a week and see how you feel after eating it."

Sherlock doesn't say anything in reply.

"Think of it as an experiment," John suggests in the hopes that Sherlock will get involved.

Still, there is no reply from Sherlock. Something is _wrong_.


	2. And Hence

Five minutes, they've been home five minutes and Mycroft has began ringing his mobile. John has put it on silent several times now, but the ring-tone always seems to come back on even louder than it was before. He shakes his head and begins to read all of the ingredients on a cereal box, "Wheat and cinnamon." he mutters to himself as he puts the cereal box into a large box that he's going to carry down to Mrs. Hudson. He glances around at all the cabinets and sighs, they are all nearly bare. He'll need to run to Tesco tonight.

With how empty the cabinets were before he started to empty all the allergy foods out it doesn't take him but three more minutes to finish. He takes one look in the fridge, shakes his head, and tosses everything (including the damn half-dissected turtle) into the bin. "I'm running out to Tesco!" he shouts in the direction of the sitting room. He debates bringing his mobile, but decides to leave it since it is still ringing. John picks up the box and heads down stairs. He goes to knock on Mrs Hudson's door, but the door moves before his hand has a chance to reach it.

"Oh!" Mrs. Hudson says, sounding delighted, "Hello, John!"

He nods, "Hello Mrs. Hudson. I was just coming down to ask if you wanted any of this food," he pats the box.

She looks skeptical, "Has he done something to it?"

"No, he hasn't." John chuckles, then he stops, '_Not that I know of_', he thinks. He shakes his head to rid rid of that train of thought, "We found out he's allergic to quite a few things today, we're cutting them out for the time being."

"Oh the poor dear!" the clicks her tongue, "I'll just bring him some biscuits to cheer him up."

John clears his throat awkwardly, "He can't have biscuits, Mrs. Hudson. He needs to be avoiding wheat, eggs, and milk for the time being."

"Goodness!" she puts a hand to her mouth, "I can hardly think of anything that doesn't have any of that in it."

He grimaces, "I know. I'm going to Tesco to try and find some things that he can eat." he sets the box on the floor, "Oh, let me give you a list of what he can't have." he fumbles around in his pocket for a few seconds before slipping out a folded piece of notebook paper, "Since you're always cooking for us it would be best for you to know what not to give him."

She takes it and skims through, clicking her tongue, "Well I'd better let you get on to Tesco, love. You certainly have quite the task."

John nods and waves his farewell as he leaves.

* * *

As he continues slamming the cereal box after cereal box back onto the shelf to reach for another he is reciting part of The List under his breath. "Wheat, egg, milk, cinnamon. Wheat, egg, milk, cinnamon." '_Damn this,_' he thinks as violently as one can think something, '_Damn the food industry for making wheat their main ingredient._'

People pass by him, nearly pressing themselves up against the other side of the aisle to keep their distance.

He finally finds a box of off-brand Coco Puffs called Chocolate Poofs and tosses it into his trolley. The shopping trolley is pathetically lacking in food items, only containing vegetables and fruits at the current time. He also had nine cartons of different milks (rice, almond, and soy) in various flavors (normal, vanilla, and chocolate).

John tilts his head back to stair at the florescent lights overhead, letting the light burn its self into his eyes so he sees purple lines when he moves.

He slowly makes his way to the condiments aisle and ketchup is worse than the cereal, in fact, he isn't able to find anything without onion powder in it. Only after he has finished reading through the minuscule print on the three dozen brands of ketchup, his hand flies up and he smacks himself in the face, '_Dammit, John, you idiot!_' he internally swears,'_Tomatoes!_'. He moves on down the aisle, a pink and hand-shaped mark on his left cheek.

Peanut butter is a blessing, seeing that their normal brand is clean, as is the jam. When he passes by the mayonnaise he remembers that it contains eggs and doesn't even try to have any sort of wishful thinking.

Bread is Hell. He spends just over an hour attempting to find any type of bread without wheat in it. He checks the cheap factory stuff, the all natural and extremely overpriced stuff, buns, roles, he even looks at waffles. In the end he puts a large buy-in-bulk type box of rice cakes in the trolley.

Skimming the aisles John picks up little things, honey, oats, crackers made of rice, actual rice, plain crisps, lactose free chocolate, raisins, chips that were buy-one-get-one-free, hot dogs to company the chips, ham, mustard, salad dressing, and enough lettuce to feed a small rabbit army.

John finally joins the queue and sighs in relief. When he notices the sliding doors a horrible realization washes over him. It is currently pitch black out. He pulls his sleeve up to check his watch, "Shit." he curses. Not realizing that he'd said that out loud until he received a pair of disapproving looks from a couple with a toddler in their trolley. Clearing his throat he goes back to staring at his watch. It's currently 10:14. Sherlock's appointment had been at 1:30 and lasted less than an hour. He'd gone out less than an hour after arriving back at the flat. So that's what? Six, seven hours? John swears again, making sure to keep it mental this time. His turn arrives and he loads his trolley onto the belt.

"That'll be 57 pounds right on the nose." the young man says and John nods, turning to run his card.

* * *

Seeing no other option he begins kicking the door and shouts, "Sherlock! Mrs. Hudson! Someone please get the door!" his arms are shaking, his right hand is numb from where the bags he's carrying have cut off his circulation. He had been so preoccupied with finding food that he didn't consider the fact that he would have to carry it all at once. He kicks again, "It's me, open up!" Finally the lock clicks and the door is opened.

"Beans." Sherlock demands, holding out both his hands in the way a four-year-old might say 'sweets.'.

John's arms are ready to give out and he shoves past Sherlock to place the groceries on the floor, "What?" he pants, awkwardly pawing at the twisted plastic to get off his arms.

"Baked beans. Did you get them?" Sherlock's arms are still extended.

He shakes his head, "What? No, you didn't ask. Plus, I'm sure they all would have had onion powder in them."

Sherlock nods sharply and turns to head back up to the flat.

"Oh no you don't! Help me carry this up." John doesn't think he can handle carrying much weight at the moment with his arms feeling like jam. "You can grab the heavier bags this time."

Quickly swooping down Sherlock picks up at least half of the bags at once, not even stumbling with the added weight. He takes the stairs two at a time.

John sighs and shifts the handles of the remaining bags up to his elbows, knowing he'd drop them otherwise. When he makes it up to the flat he trips over the bags that Sherlock left in the door way, flailing his arms and landing in a way that had the box of rice cakes pressing uncomfortably into his stomach. The air has been knocked out of him and he flips himself onto his back and arches his spine to stretch his diaphragm. "Dammit, Sherlock!" John rasps.

Sherlock continues sitting at John's laptop, typing unbelievably quickly and not paying any mind to his flatmate's suffering.

John slowly pushes himself up, wincing at the pain in his stomach and left elbow that he fell on. "Don't worry about me, I'm fine." he grumbles. When he's completely up he kicks the groceries out of the doorway so no one else will fall. He stomps over to Sherlock and yanks his computer out from under the typing fingers, "Go put the cold stuff away." When Sherlock doesn't move a centimeter, not even to look at him as he speaks, John snaps, grabbing Sherlock by the front of his shirt, "Put the _damn_ hot dogs in the _bloody_ freezer."

Apparently Sherlock is in a rolling chair because he pushes his sock covered feet into John's shins and begins drifting backwards.

Half of John wants to march upstairs and slam his door, but the other half of him remembers that those were some damn expensive hot dogs. He turns on his heels and goes back to search through the bags for those hot dogs. When he finds them he chucks them into the freezer, slams that door, then marches up the stairs and slams his own.

Only after he climbs into bed does his stomach begin growling. He groans and ignores it so he won't have to make a return trip downstairs.


End file.
